At the start of this tour, Mitchell Johnson and Andrew Flintoff were universally identified as the bowlers most pivotal to the outcome of the series. Who would have predicted, then, that a more likely candidate for the accolade might be a man who shares a name with a root vegetable – or perhaps a long-necked bird?

It was Graham Onions and Graeme Swann who tip-toed on to the stage to concentrate Australian minds to the point of anxiety and give England a good chance of victory tomorrow.

It has been that sort of series, one of preconceived thoughts shaken, of old assumptions about superiority challenged in almost every session. It clearly is a summer of change, one in its own way almost as engaging as that of 2005.

Flintoff stuck to the script at Lord's, winning the second Test for England. But the prospect of his doing it again with the ball – even if he will be able or allowed to drag himself to the starting line at Headingley on Friday – did not look a given yesterday, despite his heroics with the bat.

He heaved his way through four ineffectual overs, almost for show, guarding his wounded knee at the top of Australia's second innings, and the uncomfortable thought occurred that we might have seen the last of him in Test cricket, except maybe as a batsman, and that is a marginal call.

Johnson? After the most embarrassing disappearance since the Titanic, he has surfaced in the some-time lake that is Edgbaston to remind doubters that, when the gears click, he is the best bowler in the world.

There is no doubt that a left-arm fast bowler who can hit 90 miles an hour and swing the thing like Benny Goodman is entitled to be revered. But not when he bowls like his mother. He was almost his old self against Northamptonshire last weekend, but only in the eyes of his kindest critics.

Here he has done valiant service for Australia, fighting against his eccentric action, struggling not to let that left shoulder dip as he approaches the crease. On day four of the third Test, he bowled well. Not brilliantly, not with consistent, irresistible menace. Just well. As he should do.

And while he was clearly Australia's best hope of a breakthrough so ordinary were his partners, Ben Hilfenhaus in the morning apart, and so poor had he been in the first two Tests, especially at Lord's, his efforts were acclaimed out of all proportion to the facts: a strike rate of a wicket every 66 deliveries and an economy rate of 4.38 runs for each of his 21 overs.

This is a poor Australian attack, one which England's batsmen, even the tailenders, flayed at an average of 4.02 an over, sometimes nearly six an over, briefly at 10 an over.

The batting on either side you can safely assume is going to thrill and disappoint in equal measure, but there was abundant evidence again today, that these Australian bowlers are not to be trusted to live up to the expectations we have of them.

Shane Watson, for a start, was supposed to be insurance for the flaky spearhead Johnson, an assumption that looked idiotic as he lumbered in as if his trousers were held up by a two-stone belt. At times it seemed Johnson was cover for Watson, who is more impressive now as an opening batsman.

The bowlers have not been helped by a selection policy more conservative than a UKIP manifesto, but who would have predicted at the start of play that their best bowler would be Johnson? Johnson, of course, because, despite his quiet demeanour, he is deceptively determined.

On a wicket that has given up Warwickshire 17 draws in their past 20 matches, swing bowlers such as Johnson and Hilfenhaus might have thought about taking the pitch out of the equation. They did not always do so.

The momentum shifted from caution to adventure when Hilfenhaus ended his 14-over spell, and Watson was introduced. If Stuart Clark had been coming on then, it is unlikely the attack would have leaked 50 runs in 38 balls, 23 of them coming from Watson's three insipid overs. After three overs of towering mediocrity he took his sweater and his injured pride off to cover point. He did not return.

At least Johnson was rewarded for his endeavours – "at long, bloody last," as an Australian admirer in the press box observed – when he worked Ian Bell over with an impressive selection of bouncers before finally persuading Rudi Koertzen that a ball striking the batsman's pads and heading without impediment towards the stumps is regarded by most umpires as out.

It came way too late, perhaps, 35 runs after an identical delivery the previous session – two days previously, as it happens – had failed to excite Rudi. But it was sweetness itself for Mitch. It had broken the spell, given him some sort of lift and self-belief.

There is much to admire about the big Queenslander, and it is not just his good manners and dignity as his life and career daily resemble a sheepdog being tumble-dried in a giant laundromat. When he bats some time today he will have his chance to do what Fred did with the bat, and prove there's more to him than merely the things we expect of him.